Arrenurus cuspidifer Piersig, 1896

Zawal, Andrzej, 2008, Morphological characteristics of water mite larvae of the genus Arrenurus Dugès, 1834, with notes on the phylogeny of the genus and an identification key, Zootaxa 1765 (1), pp. 1-75 : 32

Arrenurus cuspidifer Piersig, 1896

( Fig. 18 )

Material examined: 10 larvae deriving from 1 female.

Larvae relatively small: idiosoma 176–180 µm long.

Dorsum: Dp small (DpL: 176–180 µm; DpW: 136–140 µm), egg-shaped, posterior margin rounded. Antero-lateral indents shallow, obtuse-angled, about 1/6 and 1/4 of dorsal plate’s length and width, respectively. DpW/Mp1-Mp1 2.6. Lp2, Mh1 smooth. Mp1-Mp1 relatively long (52–56 µm), longer than Mp2-Mp2 (42–45 µm); Mp1-Lp2 short (30–36 µm). Venter: CpIm (54–62 µm) almost twice length of CpIIm (28–29 µm), CpIIm slightly longer than CpIIIm (23–24 µm). CpI:CpII:CpIII ratio 2.5:1.2:1. Cp setae smooth. C1, C4 located close to Cpm. C4-CpIIIm (27–29 µm) twice that of C1-CpIm (13–15 µm). C1-C2 short (35–38 µm). Expp pentagonal, clearly wider than long. Exp located below mid-point of plate, about at level of E2. Palps: PIII 1 bipectinate; PIV1 relatively large; setae on PV relatively thin. Chelicerae: First segment bottle-shaped (63–68 µm), somewhat curved at end, relatively short. Legs: Shorter than body; LI< LII = LIII ( Fig. 4 ). ITi8 thin, short; IITi10, IIITi10 located at distal end of tibia. IIITa13 smooth. Hosts: Lestes dryas Kirby , Ischnura elegans ( Davids 1997; Baker et al. 2007).

Figures

FIGURE 4. Diagram of proportions of leg (LI<LII=LIII) and body length.

FIGURE 18. Arrenurus cuspidifer: A—ventral side, B—dorsal plate, C—excretory pore plate (scale bars: A, B— 100 µm; C—10 µm).